The invention concerns a medical electrode, in particular for energy transmission, comprising at least one electrically contactable conductor surface preferably provided with a connecting bar or the like.
Such electrodes are applied to the skin of the patient for the most widely varying purposes, for example in order to monitor bioelectrical processes of the body or to introduce into or take from the body currents—which are mostly of relatively high frequency—(for example neutral electrodes, stimulation electrodes and defibrillation electrodes). The structure of those electrodes can be of various different kinds, in general such electrodes have a rearward carrier remote from the skin and comprising a foam material. Provided on the carrier, possibly with the interposition of intermediate layers, are electrically conductive conductor surfaces, for example an aluminum laminate. It is however also possible to provide non-metallic conductor surfaces. In the case of neutral electrodes, they are not directly in contact with the skin, to avoid the occurrence of high local current densities. On the contrary, there is provided an adhesive gel which is electrically conductive for the alternating currents used and which makes the contact with the skin.
In the case of neutral electrodes for taking current from an area of operation it is already known for those electrodes to be equipped with at least two electrically separate conductor surfaces, wherein an electronic evaluation device individually monitors the currents taken from the respective conductor surfaces and gives an alarm in the event of an excessive difference being detected. The purpose of that procedure is to ensure that both conductor surfaces of the neutral electrode afford good electrical contact with the skin in order to exclude local heat-generation phenomena at the skin of the patient. In the case of the known neutral electrode, there are for example two substantially rectangular conductor surfaces which are arranged on a common carrier in mutually juxtaposed relationship with a gap between them. So that this neutral electrode together with the monitoring device connected thereto is operable, the gap must be precisely oriented with respect to the area of operation as otherwise the two conductor surfaces are supplied differently with current.